1. Field of the Invention
The invention relates to hybrid combination magnetic resonance (MR) and positron emission tomography (PET) scanning systems, and more particularly to MR/PET scanning systems having patient tables with MR local coil connectors adapted for selective coupling of a so-called auxiliary MR local coil array to the table and the MR scanning portion of the hybrid scanner.
2. Description of the Prior Art
In the past, MR scanners have employed selectively auxiliary MR local coil array assemblies in order to achieve higher image resolution for imaging procedures to a patient's brain and other organ parts. A local coil assembly has been mechanically and electrically coupled to the patient table by way of local coil connectors mounted on the table. Often the local coil connectors are oriented at the head and foot of the patient table. The local coil connectors in turn were coupled to the MR scanner by local coil cables.
In order to inhibit radio frequency (RF) electromagnetic coupling of the local coil cables and an MR scanner, the cables have been shielded in metalized plastic coated faraday cages having RF traps to inhibit distortion of or interference with MR scanner data acquisition. Traditionally local coil cables have been routed down the axial centerline of an MR scanner: the location of a patient's spine during scan data acquisition. While such local coil cable routing is satisfactory for MR scanner mode of a dual mode MR/Pet scanner, it can cause unwanted image artifacts when the hybrid seamier is operated as a PET seamier. It is believed that the such artifacts are attributable to high spatial frequency attenuation and scatter from the centerline-oriented cables, shielding and associated RF trap structures within the PET scan field of view FOV).
It would not be practical to remove and reinstall MR local coil connectors, cabling and related shielding from scanners only when imaging procedures requiring MR local coils are performed, as those components are permanently installed in the patient table structure. Existing RF shielding and traps are expensive to manufacture, relatively complex to install during scanner manufacture, and they occupy considerably higher volume within the patient table than the relatively thin MR local coil cables.
There is a need in the hybrid MR/PET scanner field to minimize formation of PET image artifacts attributable to MR local coil connectors, local MR coil cables and RF related shielding/trap structure without compromising ability to utilize MR local coil structures when needed for MR scanning procedures.
There is also a need in the hybrid MR/PET scanner field to minimize volume and construction complexity of MR local coil connectors, local MR coil cables and RF related shielding/trap structure.